Chlorinated Polyvinyl Chloride (CPVC) Pipes for Automatic Sprinkler Fire Extinguishing System - Specification

IS 16088: Scope - Key Formulas, Tables & Specifications

1. Scope Summary:

• Covers CPVC fire sprinkler pipes & fittings.
• Sampling and conformity criteria as per Table 10 and Table 12.
• Solvent cement requirements for joints in Annex D.
• Sampling procedure detailed in Annex E.

2. Key Tables:

Table 3: Kinking Resistance Test (Clause 10.5.1)

• Gives permissible bending deflections (cm) at 23°C for various pipe sizes (20mm to 80mm) and pipe lengths (1m to 14m).

(Full table covers more sizes and lengths)

Table 11: Sampling for Reversion, Vicat Softening Temp, Density

Table 12: Sampling for Resistance to External Blows at 0°C

IS 16088 Key References: Formulas, Tables & Specifications

1. Sampling & Conformity (Clause 1.8.2, 11, Annex E)

• Sampling procedures and conformity criteria are detailed in Table 10 and Table 12.
• Annex E provides specific sampling methods ensuring product compliance.

2. Kinking Resistance Test (Clause 10.5, Table 3)

• Specifies permissible bending deflections (in cm) for pipes of various sizes (20 mm to 80 mm) at SDR 13.5 and 23°C.

(Refer to full Table 3 for intermediate lengths)

3. Fire Exposure Test Setup (Annex B-1)

• Fire source: Steel pan (0.46 m², 300 mm deep) filled with 23.7 L n-heptane.
• Outer pan: 0.92 m² filled with water; fresh water flow maintained during test.
• n-Heptane properties:
  • Initial boiling point: ≥ 90°C
  • Max dry point: 100°C
  • Specific gravity: 0.69–0.73 gm/cc

4. Jointing System (Clause 10.6, Annex D)

• Solvent cement requirements for CPVC fire sprinkler pipes and fittings.

flowchart LR
  A[Sampling & Conformity] --> B[Table 10 & 12]
  A --> C[Annex E Procedures]
  D[Kinking Resistance Test] --> E[Table 3: Permissible Deflections]
  F[Fire Exposure Test] --> G[Steel Pan Setup]
  F --> H[n-Heptane Properties]
  I[Jointing System] --> J[Solvent Cement Requirements]

For detailed design and testing, always refer to the latest edition of IS 16088 and associated referenced standards.

IS 16088: Terminology & Definitions - Key Points

This standard defines terms and symbols critical for CPVC pipes and fittings:

Important Symbols & Notations

Definitions:

• Hangers (Clause 3.22): Assemblies suspending pipework from building structures.

Sampling & Conformity (Clause 11):

• Sampling procedures and conformity criteria are detailed in Annex E.
• Refer Table 10 and Table 12 for sampling specifics.

Kinking Resistance (Table 3):

• Permissible bending deflections (cm) for pipes of various diameters and lengths at 23°C (SDR 13.5).

This table guides allowable bending without kinking.

If you need formulas for design stress or pressure rating, please specify!

IS 16088: Material Requirements - Key Sampling & Conformity Specifications

Sampling & Conformity Criteria

• Sampling procedure & conformity criteria are defined in Table 10 and Table 12 (Clause 1.8.2).
• Number of test samples and acceptance criteria per lot are in Table 13 (Clause 1.9.3).
• Lot acceptance depends on the number of failing samples ≤ acceptance number (Col 4, Table 13).

Key Tables for Sampling

Table 11: Sampling for Reversion, Vicat Softening Temp & Density Tests

Table 12: Sampling for Resistance to External Blows at 0°C

IS 16088: Dimensions and Tolerances Key Points

• Clause 1.4 (E-1.4): Visual and dimensional requirements ensure pipes are free from defects and conform to specified dimensions.

• Clause 3.13:

  • Tolerance = Permitted Max Value − Permitted Min Value of a dimension.
  • Controls manufacturing variations to ensure interchangeability.

• Clause 7.1:

  • Specifies Outside Diameter (OD) and Wall Thickness as per Table 1.

• Clause 3.6:

  • Defines Maximum Mean Outside Diameter (dem, Min) as the upper limit of the average OD for a nominal pipe size.

Table 1: Typical Dimensions and Tolerances (Excerpt)

(Note: Refer to IS 16088 Table 1 for full details.)

Formula for Tolerance Check:

[ \text{Tolerance} = \text{Permitted Max} - \text{Permitted Min} ]

Where:

• Permitted Max = Specified dimension + tolerance
• Permitted Min = Specified dimension − tolerance

flowchart LR
A[Specified Dimension] --> B{Apply Tolerance}
B --> C[Permitted Max = Spec + Tol]
B --> D[Permitted Min = Spec - Tol]
C & D --> E[Check Actual Dimension]
E --> F{Within Limits?}
F -->|Yes| G[Accept]
F -->|No| H[Reject]

Summary: IS 16088 mandates strict control on pipe OD and wall thickness tolerances to ensure quality and fitment, with detailed values in Table 1 and definitions

IS 16088: Mechanical Properties Key Points

1. Tensile Strength (Clause 10.4)

• Tested per IS 12235 (Part 13)
• Minimum tensile strength at yield: 53 MPa at 27 ± 2℃

2. Kinking Resistance Test (Clause 10.5.1 & Table 3)

• Deflection increases with pipe length (see full Table 3 for values up to 14 m length).

3. Sampling & Conformity (Clause 11, Annex E)

• Sampling sizes and acceptance/rejection criteria depend on lot size.
• Example from Table 11 for tensile-related tests:

Summary

• Tensile strength ≥ 53 MPa @ 27°C
• Kinking resistance varies by pipe size and length (see Table 3)
• Sampling criteria strictly defined for quality control

flowchart LR
    A[Tensile Strength Test] -->|Min 53 MPa| B[Pass/Fail]
    C[K

IS 16088: Fire Performance & Flammability Tests Key Points

Fire Exposure Test (Clause 1.1, Table B-1)

• Fire source: Square steel pan, 0.46 m² area, 300 mm deep, steel thickness ≥ 6.4 mm.
• Filled with 23.7 liters of n-heptane (Boiling point 90-100°C, Specific gravity 0.69-0.73 gm/cc).
• Pan placed inside a larger 0.92 m² water-filled pan, 300 mm deep, with water flow during test.

Flammability Test (Annex C)

• Test on 5 specimens of CPVC pipe (40 mm diameter).
• Criteria for V-0 rating:
  • Total after-flame time (t1 + t2) ≤ 50 s for all 5 specimens.
  • No flaming particles or drops igniting cotton indicator.
• If 1 specimen fails, repeat test on another 5.
• If total after-flame time is 51-55 s, repeat test once.

Flame Application Procedure (Clause 6.5)

• Flame applied for 10 ± 0.5 s at 10 ± 1 mm distance.
• Measure after-flame times:
  • t1: After first flame application.
  • t2: After second flame application.
  • t3: Afterglow time after second flame.
• Use cotton indicator to detect flaming particles.

Summary Table: Flammability Test Times

flowchart TD
    A[Start Test] --> B[Apply Flame 1 (10 s)]
    B --> C[Measure t1 (after-flame)]
    C --> D[Apply Flame 2 (10 s)]
    D --> E[Measure t2 (after-flame) & t3 (afterglow)]
    E --> F{Check Criteria}
    F -->|Pass| G[Test Complete

IS 16088 - Sampling and Acceptance Criteria (Annex E, Clause 11)

Key Points:

• Acceptance tests are performed on samples from a lot to decide lot acceptance (Clause 3.15.2).
• Sampling and acceptance criteria are specified in Table 10, Table 11, Table 12, and Table 13.

Table 11: Sampling for Reversion, Vicat Softening Temperature & Density Test

Table 12: Sampling for Resistance to External Blows at 0°C

IS 16088: Type Tests and Quality Control Key Points

1. Type Tests (Clause 3.15.1)

• Conducted when composition or size/series changes.
• Purpose: To establish suitability and performance of pipes.

2. Sampling and Acceptance Criteria

Table 11: Sampling for Reversion, Vicat Softening Temp, Density Tests

Table 12: Sampling for Resistance to External Blows at 0°C

IS 16088: Hydrostatic Pressure Tests Key Points

1. Internal Hydrostatic Pressure Test (Short Term - Acceptance Test)

• Clause 1.9 (E-1.9) & Clause 10.1.1
• Test pressure = 5 × Rated Pressure
• Duration = 1 minute at room temperature
• No rupture, leakage, or separation allowed
• Procedure per IS 12235 (Part 8/Sec 1)

2. Internal Hydrostatic Pressure Test (Long Term - Type Test)

• Clause 2.7 (E-2.7)
• Conducted for type approval
• Pressure and duration as per design/type requirements (usually sustained pressure for several hours or days)
• Checks long-term strength and durability

3. Hydrostatic Characteristics (Clause 10.1)

• Defines test conditions and acceptance criteria
• Ensures pipe integrity under internal pressure

Summary Table: Short Term Hydrostatic Test

Reference:

• IS 12235 (Part 8/Sec 1) for detailed test procedure
• Use calibrated pressure gauges and proper safety measures

flowchart LR
    A[Pipe Sample] --> B[Apply Internal Pressure]
    B --> C{Pressure = 5 × Rated Pressure?}
    C -- Yes --> D[Hold for 1 min]
    D --> E{No Leakage or Rupture?}
    E -- Yes --> F[Pass Test]
    E -- No --> G[Fail Test]
    C -- No --> G

This ensures pipe quality and safety under operational pressures.

IS 16088: Installation and Jointing Procedures for CPVC Fire Sprinkler Pipes

Key Specifications & Procedures

• Solvent Cement Jointing (Clause 2.4 & Annex D):

  • Apply solvent cement on pipe and fitting socket.
  • Immediately insert pipe into fitting socket, rotate 1/4 turn while inserting, not after bottoming.
  • Pipe must bottom out at fitting stop.
  • Hold assembly for 30 seconds to ensure initial bonding.
  • A continuous bead of cement should be visible around the joint.
  • Excess cement wiped off; insufficient cement joints must be discarded.

• Cure Times (Annex D-3 & Table 5):

Note: For ≥50 mm pipes, solvent cement application below 4.4°C requires warming to ≥4.4°C and curing before pressurizing.

• Handling:
  • After initial set (1-5 min), handle carefully avoiding joint stress.
  • Allow sprinkler fittings to cure minimum 30 min before installing sprinklers.
  • Anchor pipes to prevent rotation during installation.

Table 3: Permissible Bending Deflections (SDR 13.5 at 23°C)

IS 16088: Hydraulic Design Key Points

1. Hydraulic Calculations (Clause 7.1)

• Use Hazen-Williams equation for CPVC pipes.
• C factor = 150 (smoothness coefficient)

2. Pipe Friction Loss (Clause 7.2)

• Friction loss formula (Hazen-Williams):

[ h_f = 10.67 \times \frac{L}{C^{1.85} \times d^{4.87}} \times Q^{1.85} ]

Where:

• (h_f) = head loss (m)
• (L) = pipe length (m)
• (C) = Hazen-Williams coefficient (150)
• (d) = internal diameter (mm)
• (Q) = flow rate (L/s)

3. Temperature Difference (Clause 9.1)

• Design temperature difference, (\Delta T = 40^\circ C)

4. Length of Loop (Clause 9.1, 10.7, 12.2, 13.7, 15.2, 21.3)

• Lengths specified in mm for hydraulic loop design; ensure loop length complies with these clauses for pressure and flow optimization.

Summary Table: Hazen-Williams C Factor for CPVC

flowchart LR
    A[Water Source] --> B[CPVC Pipe]
    B --> C[Hydraulic Loop]
    C --> D[Outlet]
    B -. Friction Loss (hf) .-> E[Calculate using Hazen-Williams]

Note: Always verify pipe diameter and flow rate for accurate friction loss and pressure drop calculations.

IS 16088: Resistance to External Damage Key Points

1. Resistance to External Blow at 0°C (Clause 10.2)

• Test method: Per IS 15778 with falling weight impact test.
• Acceptance: True impact rate ≤ 10%.
• Classified striker mass and drop height (Table 2):

2. Kinking Resistance Test (Clause 10.5, Table 3)

• Permissible bending deflections (cm) for SDR 13.5 pipes at 23°C vary by pipe size and length.
• Example: For 20 mm pipe length 1 m, deflection = 8.6 cm; length 5 m, deflection = 214.2 cm.

3. Sampling and Criteria (Clause 11)

• Sampling sizes and acceptance/rejection criteria for external blow resistance tests are per Table 12.
• Example: For lot size 3,001 to 10,000 pipes, first sample size = 3, acceptance number = 0, rejection number = 2.

Summary Diagram: Falling Weight Impact Test Setup

graph LR
A[Falling Weight] --> B[Drop Height]
B --> C[Pipe Sample at 0°C]
C --> D[Impact Test per IS 15778]
D --> E{Impact Rate ≤ 10%?}
E -->|Yes| F[Pass]
E -->|No| G[Fail]

Note: Ensure test conditions strictly follow IS 15778 and acceptance criteria per IS 16088.

IS 16088: Marking and Packaging — Key Points

1. Marking (Clause 12.2.1)

• Pipes must bear the BIS Standard Mark as per the Bureau of Indian Standards Act, 1986.
• Licensing conditions for use of the Standard Mark are governed by BIS rules.
• Marking ensures traceability and conformity to standards.

2. Packaging

• Packaging should protect pipes/fittings from damage during transport and storage.
• Must maintain product integrity and facilitate easy handling.
• Packaging details are generally specified by manufacturers under BIS guidelines.

3. Related Testing and Sampling

• Sampling and conformity criteria are given in Annex E.
• Kinking resistance test values (Table 3) provide permissible bending deflections for pipes of different sizes and lengths, ensuring packaging does not induce damage.

(Values increase with pipe length; see full table in Clause 10.6)

Summary Diagram: Marking & Packaging Flow

flowchart TD
    A[Manufacturing] --> B[Marking with BIS Standard Mark]
    B --> C[Quality Inspection & Testing]
    C --> D[Packaging as per BIS Guidelines]
    D --> E[Storage & Transport]
    E --> F[End User / Installation]

Note: Refer to BIS licensing for Standard Mark use and Annex E for sampling/testing procedures. Packaging must prevent damage, considering kinking resistance limits.

IS 16088: Safety and Handling Guidelines - Key Points

1. Fire Exposure Test (Clause 1.1, Table B-1)

• Fire source pan size: 0.46 m², 300 mm deep, steel ≥ 6.4 mm thick.
• Fuel: 23.7 liters of n-heptane (Boiling point: 90-100°C, Specific gravity: 0.69-0.73 gm/cc).
• Outer pan: 0.92 m², 300 mm deep, filled with water, continuous water flow during the test.
• Purpose: Simulates fire exposure for pipe/fitting testing.

2. Kinking Resistance Test (Clause 10.6, Table 3)

• Permissible bending deflections (cm) depend on pipe size (20 to 80 mm) and length (1 to 14 m).
• Example: For 20 mm pipe at 1 m length, max bending deflection = 8.6 cm.
• Used to ensure pipes resist permanent deformation under bending.

3. Flammability Test (Clause 9.7)

• Pipes/fittings must pass V-0 rating as per Annex C (UL 94 standard).
• Ensures material self-extinguishes quickly after ignition.

4. Jointing System (Clause 10.6)

• Use solvent cement as per Annex D for CPVC fire sprinkler pipes and fittings.

Summary Diagram: Safety Test Flow

flowchart TD
    A[Prepare Fire Source Pan] --> B[Fill with 23.7 L n-Heptane]
    B --> C[Place in Outer Water Pan]
    C --> D[Conduct Fire Exposure Test]
    D --> E[